| Message ID | 20220209134018.8242-1-liuyuntao10@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | hugetlbfs: fix a truncation issue in hugepages parameter | expand |
On 2/9/22 05:40, liuyuntao wrote: > From: Liu Yuntao <liuyuntao10@huawei.com> > > When we specify a large number for node in hugepages parameter, > it may be parsed to another number due to truncation in this statement: > node = tmp; > > For example, add following parameter in command line: > hugepagesz=1G hugepages=4294967297:5 > and kernel will allocate 5 hugepages for node 1 instead of ignoring it. > > I move the validation check earlier to fix this issue, and slightly > simplifies the condition here. > > Fixes: b5389086ad7be0 ("hugetlbfs: extend the definition of hugepages parameter to support node allocation") > Signed-off-by: Liu Yuntao <liuyuntao10@huawei.com> > --- > mm/hugetlb.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 61895cc01d09..0929547f6ad6 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -4159,10 +4159,10 @@ static int __init hugepages_setup(char *s) > pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); > return 0; > } > + if (tmp >= nr_online_nodes) > + goto invalid; > node = tmp; I am surprised none of the automated checking complained about that assignment. > p += count + 1; > - if (node < 0 || node >= nr_online_nodes) I can't remember, but I think that check for node < 0 was added to handle overflow during the above assignment. Do you remember Zhenguo Yao? > - goto invalid; > /* Parse hugepages */ > if (sscanf(p, "%lu%n", &tmp, &count) != 1) > goto invalid; Thanks, Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
On 2022-02-10 0:43 UTC, Mike Kravetz wrote: > On 2/9/22 05:40, liuyuntao wrote: > > From: Liu Yuntao <liuyuntao10@huawei.com> > > > > When we specify a large number for node in hugepages parameter, > > it may be parsed to another number due to truncation in this statement: > > node = tmp; > > > > For example, add following parameter in command line: > > hugepagesz=1G hugepages=4294967297:5 > > and kernel will allocate 5 hugepages for node 1 instead of ignoring it. > > > > I move the validation check earlier to fix this issue, and slightly > > simplifies the condition here. > > > > Fixes: b5389086ad7be0 ("hugetlbfs: extend the definition of hugepages parameter to support node allocation") > > Signed-off-by: Liu Yuntao <liuyuntao10@huawei.com> > > --- > > mm/hugetlb.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > index 61895cc01d09..0929547f6ad6 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -4159,10 +4159,10 @@ static int __init hugepages_setup(char *s) > > pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); > > return 0; > > } > > + if (tmp >= nr_online_nodes) > > + goto invalid; > > node = tmp; > > I am surprised none of the automated checking complained about that > assignment. I think such assignments may be very common in kernel, and thus automated checks just ignore them. > > > p += count + 1; > > - if (node < 0 || node >= nr_online_nodes) > > I can't remember, but I think that check for node < 0 was added to handle > overflow during the above assignment. Do you remember Zhenguo Yao? No, I don't. I took a look and found that the check for node < 0 has been there since his first version of patch. > > > - goto invalid; > > /* Parse hugepages */ > > if (sscanf(p, "%lu%n", &tmp, &count) != 1) > > goto invalid; > > Thanks, > > Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> > > -- > Mike Kravetz -- Liu Yuntao
Mike Kravetz <mike.kravetz@oracle.com> 于2022年2月10日周四 08:44写道： > > On 2/9/22 05:40, liuyuntao wrote: > > From: Liu Yuntao <liuyuntao10@huawei.com> > > > > When we specify a large number for node in hugepages parameter, > > it may be parsed to another number due to truncation in this statement: > > node = tmp; > > > > For example, add following parameter in command line: > > hugepagesz=1G hugepages=4294967297:5 > > and kernel will allocate 5 hugepages for node 1 instead of ignoring it. > > > > I move the validation check earlier to fix this issue, and slightly > > simplifies the condition here. > > > > Fixes: b5389086ad7be0 ("hugetlbfs: extend the definition of hugepages parameter to support node allocation") > > Signed-off-by: Liu Yuntao <liuyuntao10@huawei.com> > > --- > > mm/hugetlb.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > index 61895cc01d09..0929547f6ad6 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -4159,10 +4159,10 @@ static int __init hugepages_setup(char *s) > > pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); > > return 0; > > } > > + if (tmp >= nr_online_nodes) > > + goto invalid; > > node = tmp; > > I am surprised none of the automated checking complained about that > assignment. > > > p += count + 1; > > - if (node < 0 || node >= nr_online_nodes) > > I can't remember, but I think that check for node < 0 was added to handle > overflow during the above assignment. Do you remember Zhenguo Yao? > Sorry for my late reply. This check for node < 0 was added to handle node parameter overflow from the earliest version: https://lore.kernel.org/lkml/20210820030536.25737-1-yaozhenguo1@gmail.com/ Parameter of node allocation was: hugepages_node=xx hugepages=xx at this version. With the changing of the code, this check has lost its effect. > > - goto invalid; > > /* Parse hugepages */ > > if (sscanf(p, "%lu%n", &tmp, &count) != 1) > > goto invalid; > > Thanks, > > Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> > > -- > Mike Kravetz
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 61895cc01d09..0929547f6ad6 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4159,10 +4159,10 @@ static int __init hugepages_setup(char *s) pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); return 0; } + if (tmp >= nr_online_nodes) + goto invalid; node = tmp; p += count + 1; - if (node < 0 || node >= nr_online_nodes) - goto invalid; /* Parse hugepages */ if (sscanf(p, "%lu%n", &tmp, &count) != 1) goto invalid;